Auxiliary yarn start-up wheel and method for draw false twist machines

ABSTRACT

This invention relates to an auxiliary yarn start-up wheel and method. The previously known auxiliary wheel consisted of a rotatable disc driven by the winder drive roll on the draw false twist machine, this disc in turn, by means of gears and a magnetic clutch, drives the auxiliary start-up wheel. The improvement is providing a weight to get better friction drive, providing a ceramic guide with multiple grooves, and providing at least a 4 pole magnet as part of the magnetic clutch. In the prior art method, the yarn passed over a simple wire guide and had contact with the rotating auxiliary wheel to slightly increase tension on the yarn that had been strung up through the threadpath of the machine. The yarn did not move. In the improved method, the yarn still does not move, but tension on the yarn can be increased at least two-fold by wrapping the yarn at least two and one-half times about the start-up wheel and the modified ceramic guide so the start-up wheel stops rotating but the magnetic clutch slips, applying torque to the wheel. By means of this method and improved start-up wheel, yarn begins to move as soon as the drive roll prior to false twist spindle is engaged. The prior art wheel and method did not move the yarn until the drive rolls both prior to and immediately after the false twist spindle were engaged.

United States Patent Beringer et al.

[ 1 AUXILIARY YARN START-UP WHEEL AND METHOD FOR DRAW FALSE TWIST MACHINES [75] Inventors: Charles William Beringer; Marion Archer Wilder, Jr., both of Columbia, SC.

[73] Assignee: Allied Chemical Corporation,

Morristown, NJ.

[22] Filed: June 12, 1972 [21] Appl. No.: 261,838

[52] U.S. Cl 57/34 HS, 57/90, 57/106,

[51] Int. Cl D02g 1/02 [58] Field of Search 57/34 HS, 77.3-77.45,

57/106, 157 TS, 34 R, 90

[56] References Cited UNITED STATES PATENTS 3,041,813 7/1962 Enngking 57/34 HS 3,443,371 5/1969 Ward 57/34 HS 3,435,603 4/1969 Rice 57/34 HS 3,475,896 11/1969 Gibson et al.... 57/106 3,559,391 2/1971 Rice 57/34 HS 3,645,081 2/1972 Salama 57/34 HS Feb. 26, 1974 5 7] ABSTRACT This invention relates to an auxiliary yarn start-up wheel and method. The previously known auxiliary wheel consisted of a rotatable disc driven by the winder drive roll on the draw false twist machine, this disc in turn, by means of gears and a magnetic clutch, drives the auxiliary start-up wheel. The improvement is providing a weight to get better friction drive, providing a ceramic guide with multiple grooves, and providing at least a 4 pole magnet as part of the magnetic clutch. In the prior art method, the yarn passed over a simple wire guide and had contact with the rotating auxiliary wheel to slightly increase tension on the yarn that had been strung up through the threadpath of the machine. The yarn did not move. In the improved method, the yarn still does not move, but tension on the yarn can be increased at least two-fold by wrapping the yarn at least two and one-half times about the start-up wheel and the modified ceramic guide so the start-up wheel stops rotating but the magnetic clutch slips, applying torque to the wheel. By means of this method and improved start-up wheel, yarn begins to move as soon as the drive roll prior to false twist spindle is engaged. The prior art wheel and method did not move the yarn until the drive rolls both prior to and immediately after the false twist spindle were engaged.

7 Claims, 6 Drawing Figures iATENTEmiazs 1914 V 3793x317 SHEET 2 0F 5 FIG? PATENTEUFEB26 m4 SHEET 5 BF 5 AUXILIARY YARN START-UP WHEEL AND METHOD FOR DRAW FALSE TWIST MACHINES BACKGROUND OF THE INVENTION This invention relates to an improved method to process textile yarn, specifically to an auxiliary yarn startup wheel and method to start-up draw false twist machines.

The prior art auxiliary yarn start-up wheel apparatus is shown in FIG. 3. The device consists of a frame 1 having mounted thereon a rotatable disc 2 which through means of gears and a magnetic clutch drives a start-up wheel 9. Power for this start-up wheel is provided from the draw false twist machine winder drive roll 26. The prior art magnetic clutch has only two poles.

In use, yarn 12 is strung under wire guide 13 over rotating start-up wheel 9 into aspirator 14. Only a slight tension is added to the yarn. The wheel continues to rotate. Prior to start-up the yarn does not move even though the aspirator is pulling on it and the rotating wheel tends to move it and creates friction to add tension to it. To start up a draw false twist machine, according to the prior art, engaging a draw roll below the false twist spindle does not permit the yarn to be pulled through the false twist spindle by the prior art wheel and method. Engaging the draw roll below the false twist spindle overfeeds yarn to the false twist spindle until a drive roll upstream of the false twist spindle is engaged or until a yarn filament or filaments wrap around this drive roll to cause a breakout which can happen within 1 second. Thus, the upstream drive roll and spindle drive must be engaged at the same time as the draw roll below the false twist spindle or a breakout occurs. This requires an operator to use two hands and one foot in simultaneous action. It requires special training of highly physically coordinated persons. Since highly coordinated persons are required, some persons are unable to start-up without many breakouts even after extensive training. Each yarn breakout requires many minutes to restring the yarn along the threadpath of the draw false twist machine. Thus, machine efficiency of the prior art method of start-up was too low.

SUMMARY OF THE INVENTION The auxiliary yarn start-up wheel apparatus for a draw false twist machine of this invention is an improvement on a prior art start-up wheel apparatus comprising in combination, a frame, a rotatable disc, gears, a magnetic clutch, and the start-up wheel. The rotatable disc is mounted on the frame so that the disc can be friction-driven by any external rotating cylinder, such as the winder drive roll on the draw false twist machine. The rotatable disc has an outer diameter with a friction surface and means to drive a rotatable shaft. This means could be a gear having a diameter smaller than the outer diameter of friction surface, meshing with another gear centered axially and fixed to a rotatable shaft mounted on the frame. The drive could also be belt and pulleys. This rotatable shaft also has mounted on it a two-pole, fixed cylindrical magnet centered axially on the shaft. This magnet has its poles directed axially and in close proximity to a ferromagnetic plate fixed and centered axially within a start-up wheel rotatably mounted on the shaft. The cylindrical magnet and ferromagnetic plate act as a magnetic clutch. The start-up wheel has a friction surface adapted for contacting yarn. A smooth wire type guide is located near the wheel. The improvement comprises, in combination, first providing weight of at least 1 pound on the frame near the rotatable disc. In the device described in the Description of the Preferred Embodiments the weight added to the prior art device was 1.1 pounds. Any weight between about 1 and about 3 pounds would be useful on the improved device. In position on the draw false twist machine frame about 2.0 pounds of force was measured on the rotatable disc. Thus, a total weight of from about 1.9 to about 5.0 pounds on the disc, depending on the friction surface and the strength of the magnetic clutch, is desired for this improvement. This provides improved friction between the winder drive roll of the draw false twist machine and the rotatable disc to provide more power to the start-up wheel. The second improvement is providing a guide such as a ceramic guide with multiple grooves mounted on the frame within a few inches, preferably about 3, of the start-up wheel. The third improvement is providing at least a 4-pole magnet as a cylindrical magnet portion of the magnetic clutch. An optional improvement is providing a ferromagnetic plate having at least 2, preferably 4 poles such as by providing slots in the plate.

The method to create increased tension on continuous filament yarn during start-up of any draw false twist machine comprises improving a method whereby yarn is strung up through the threadpath of the draw false twist machine and then into an aspirator. Then, in the prior art, the yarn is contacted with the guide and startup wheel driven by the winder drive roll on the draw false twist machine. The start-up wheel is driven through a rotatable disc resting on the winder drive roll. The disc has a gear meshing with another gear on a shaft having a magnetic clutch which acts to drive the start-up wheel. Even when in contact with the yarn, the prior art wheel continues to rotate. The improved method comprises increasing the weight on the rotatable disc to increase friction between the disc and the drive roll and wrapping the yarn about a modified guide and the start-up wheel at least 2% times so that the start-up wheel being driven by the drive roll through the rotatable disc, gears and magnetic clutch stops rotating but the magnetic clutch continues to slip and apply torque to the start-up wheel. In this way, tension on the yarn in the threadpath is increased at least twofold.

Tension on the yarn can be adjusted by changing the distance between the magnet and the plate in the magnetic clutch. The distance can be between about 9.0015 inch and about 0.012 inch to operate, while the broad, preferred range is between about 0.002 inch and about 0.010 inch, the most preferred range is between about 0.002 and about 0.005 inch. The tension on the yarn with prior art method was about 65 grams. Tension can be increased to 340 grams with this invention. However, a lower tension of about grams is preferred. The higher tension, 340 grams, would break most low denier yarn. This increased tension permits the yarn to begin to move as soon as any drive roll upstream of falst twist spindle is engaged in the -thread path. Compare this with the prior art, when a drive roll prior to the false twist spindle and a drive roll after the false twist spindle as well as the spindle drive must be engaged before yarn begins to move. This invention eliminates the special coordination and skill required to simultaneously engage a drive roll prior to the false twist spindle, the drive roll after the false twist spindle, and the false twist spindle drive. Thus, with this invention, the drive roll upstream of the false twist spindle can be engaged, then the yarn begins moving. The drive roll after the false twist spindle and the false twist spindle drive can be engaged anytime after the upstream drive roll is engaged. This eliminates wrapped filaments due to overfeed on the upstream drive roll and eliminates breakouts of the yarn and the time consuming restring-up of the draw false twist machine threadpath.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of the start-up wheel of this invention, showing a portion of the frame, the rotating disc, drive means, and start-up wheel. FIG. 2 is an isometric view showing the start-up wheel apparatus of this invention and showing the start-up wheel removed to reveal the cylindrical magnet portion of the magnetic clutch. FIG. 3 is a front view of the prior art start-up wheel. FIG. 4 is a schematic showing the yarn threadpath through a draw false twist machine and the auxiliary yarn start-up wheel in place in contact with the winder drive roll and the yarn wrapped about it. FIG. 5 shows a detail of the yarn wrapped about the start-up wheel and guide. FIG. 6 shows the face of plate 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In all of the drawings, like numbers indicate the same element of the apparatus.

FIG. 1 is a cross-section of the main elements of the start-up wheel apparatus excluding only a portion of the frame. Frame 1 carries rotatable disc 2 which has a friction surface 3 and a gear 4 meshing with another gear 5 mounted on rotatable shaft 6 which also has a magnetic clutch 7 and 8 and rotating wheel 9 mounted thereon. Cylindrical magnet 7 is fixed to rotating shaft 6. Ferromagnetic plate 8 is fixed to rotatable wheel 9 having friction surface 10.

FIG. 2 is the isometric view of the auxiliary start-up wheel of this invention. Like numbers in the paragraph above describe like apparatus, and in addition, weight 11 is shown. Weight 11 is used to increase the friction between the friction surface 3 of rotatable disc 2 when it is engaged with a winder drive roll, not shown in the drawing.

FIG. 3 shows a prior art auxiliary start-up wheel apparatus engaged with winder drive roll 26. Yarn 12 passes under wire guide 13 and over start-up wheel 9 which is driven through gears and magnetic clutch by rotatable disc 2. Yarn 12 is finally pulled into aspirator 14. In this prior art embodiment, auxiliary start-up wheel 9 rotates even when yarn 12 engages it.

FIG. 4 shows a typical string-up of a draw false twist machine with the auxiliary start-up wheel apparatus in place. Yarn 12 from a supply creel is strung up through first drive roll 21 across curved draw plate 16 to second drive roll 22 and through texturizing heater 17 then to false twist spindle 18 and on to third drive roll 23. Yarn 12 then passes across guide 20 to fourth drive roll 24 into post set heating chamber 19 and to final drive roll 25. Auxiliary start-up wheel frame 1 rests on machine frame 27 so that rotatable disc 2 engages winder drive roll 26. Yarn 12 wraps 2% times about start-up wheel 9 and grooved guide 15 and then passes into aspirator 14. In this invention start-up wheel 9 stops rotating when wrapped with yarn.

FIG. 5 shows a detail of the 2% wraps around the start-up wheel 9 and grooved guide 15.

FIG. 6 shows the detail of the face of plate 8. The detail shown is the optional four-pole plate. Four poles are achieved by providing four slots 27 in the face of plate 8. Thus, the area between each slot forms a pole to accept magnetic flux from magnet 7 in an improved manner, strengthening the clutch by providing more torque due to magnetic force. A two-pole plate could be provided by simply making only two opposed slots 27 instead of 4 as shown.

In the prior art method, yarn is strung through the threadpath as shown in FIG. 4 with the exception that it is strung-up through the auxiliary start-up wheel as shown in FIG. 3. Thus, in the prior art method, yarn has only slight contact with the start-up wheel and the startup wheel continues to rotate even in contact with the yarn. Only when the second drive roll 22, the false twist spindle l8 drive and the third drive roll 23 are engaged would yarn begin to move in the prior art method.

In the method of this invention, yarn is strung up as shown in FIG. 4. Here again, yarn does not move but the wraps of yarn about guide 15 and start-up wheel 9 stop wheel 9 from rotating and the magnetic clutch 7 and 8 slips but imparts considerable torque to start-up wheel 9 which in turn increases tension on the yarn 12 about two-fold. This increased tension permits the yarn to be pulled through the false twist spindle as soon as any drive roll upstream of the false twist spindle is engaged. Thus, with the method of this invention, the yarn moves as soon as the second roll 22 engages. With the prior art tool and method, yarn did not move until both the second drive roll 22 andthe third drive roll 23 and false twist spindle 18 drive were engaged. Since with the prior art wheel and method, engaging the third drive roll 23 before engaging the second drive roll 22 would cause the yarn to breakout, a difficult situation of requiring precise timing of simultaneously engaging the second drive roll 22, the third drive roll 23 and the false twist spindle 18 drive is eliminated by means of this invention. Even when the prior art sequence is proper, the overfeed caused by engaging the second drive roll 22 for even a second or two before engaging the third drive roll 23 and the spindle drive often caused filaments to wrap about the second drive roll 22. This in turn caused yarn breakouts and required time to restring the entire draw false twist machine. This invention overcomes the problems of breakout due to overfeeding and filament wraps because the precise timing of the prior art start-up is not necessary. Yarn moves as soon as a drive roll, upstream of the fase twist spindle, is engaged.

We claim:

1. In an auxiliary yarn start-up wheel apparatus for a draw false twist machine comprising, in combination, a frame, a rotatable disc, an external rotating cylinder, a rotatable shaft, a cylindrical magnet, a ferromagnetic plate, and a wheel, said rotatable disc mounted on said frame so that said disc can be friction-driven by said external rotating cylinder, said disc having an outer diameter with a friction surface and said disc having means to drive said rotatable shaft mounted on said frame, said shaft having mounted thereon the said cylindrical magnet mounted fixed, centered axially on said shaft,

said magnet having poles directed axially and in close proximity to said ferromagnetic plate fixed and centered axially within said wheel rotatably mounted centered axially on said shaft, said wheel having a friction surface adapted for contacting yarn,

the improvement comprising, in combination,

a weight of at least one pound on said frame near said disc a guide with multiple grooves mounted on said frame within 3 inches of said wheel, and

said magnet having at least four poles, said magnet being spaced between about 0.0015 and about 0.012 inch from said plate.

2. The yarn start-up wheel of claim 1 wherein said grooved guide is a ceramic guide, and said magnet is spaced between about 0.002 and about 0.010 inch from said plate.

3. The yarn start-up wheel of claim 1 wherein said weight is between about 1 pound and about 3 pounds to provide a total weight on said disc of between about 1.9 pounds and about 5.0 pounds.

4. The yarn start-up wheel of claim 1 wherein said drive means is meshed gears.

5. The yarn start-up wheel of claim 1 wherein said drive means is a belt and pulleys.

6. The yarn start-up wheel of claim 1 wherein said plate face is slotted to provide at least two poles for receiving magnetic flux from said magnet.

7. In a method to create increased tension on continuous filament yarn during start-up of a draw false twist machine comprising stringing up said yarn through the threadpath of said machine, and into an aspirator, then contacting the yarn with a guide and a start-up wheel driven by a winder drive roll on said machine, said wheel driven through a rotatable disc resting on said drive roll, said disc having means to drive a shaft having a magnetic clutch acting to drive said start-up wheel the improvement comprising increasing the weight on said rotatable disc to increase friction between said disc and said drive roll, and

wrapping said yarn about a guide and said start-up wheel at least 2% times so that said start-up wheel being driven by said drive roll through said disc, drive means and magnetic clutch stops rotating, said magnetic clutch slipping but applying torque to said wheel whereby tension on said yarn in said yarn in said threadpath is increased at least two-fold. 

1. In an auxiliary yarn start-up wheel apparatus for a draw false twist machine comprising, in combination, a frame, a rotatable disc, an external rotating cylinder, a rotatable shaft, a cylindrical magnet, a ferromagnetic plate, and a wheel, said rotatable disc mounted on said frame so that said disc can be friction-driven by said external rotating cylinder, said disc having an outer diameter with a friction surface and said disc having means to drive said rotatable shaft mounted on said frame, said shaft having mounted thereon the said cylindrical magnet mounted fixed, centered axially on said shaft, said magnet having poles directed axially and in close proximity to said ferromagnetic plate fixed and Centered axially within said wheel rotatably mounted centered axially on said shaft, said wheel having a friction surface adapted for contacting yarn, the improvement comprising, in combination, a weight of at least one pound on said frame near said disc a guide with multiple grooves mounted on said frame within 3 inches of said wheel, and said magnet having at least four poles, said magnet being spaced between about 0.0015 and about 0.012 inch from said plate.
 2. The yarn start-up wheel of claim 1 wherein said grooved guide is a ceramic guide, and said magnet is spaced between about 0.002 and about 0.010 inch from said plate.
 3. The yarn start-up wheel of claim 1 wherein said weight is between about 1 pound and about 3 pounds to provide a total weight on said disc of between about 1.9 pounds and about 5.0 pounds.
 4. The yarn start-up wheel of claim 1 wherein said drive means is meshed gears.
 5. The yarn start-up wheel of claim 1 wherein said drive means is a belt and pulleys.
 6. The yarn start-up wheel of claim 1 wherein said plate face is slotted to provide at least two poles for receiving magnetic flux from said magnet.
 7. In a method to create increased tension on continuous filament yarn during start-up of a draw false twist machine comprising stringing up said yarn through the threadpath of said machine, and into an aspirator, then contacting the yarn with a guide and a start-up wheel driven by a winder drive roll on said machine, said wheel driven through a rotatable disc resting on said drive roll, said disc having means to drive a shaft having a magnetic clutch acting to drive said start-up wheel the improvement comprising increasing the weight on said rotatable disc to increase friction between said disc and said drive roll, and wrapping said yarn about a guide and said start-up wheel at least 2 1/2 times so that said start-up wheel being driven by said drive roll through said disc, drive means and magnetic clutch stops rotating, said magnetic clutch slipping but applying torque to said wheel whereby tension on said yarn in said yarn in said threadpath is increased at least two-fold. 